Thailand has confirmed a case of human bird flu which has sparked fears of possible human to human transmission.

The victim's sister and niece died from suspected bird flu earlier this month.

But the Thai government said the 32-year-old woman had been in contact with dead birds, and there was no evidence she caught the disease from relatives.

At least nine people have died from bird flu in Thailand so far this year, but all are thought to have contracted the disease from poultry.

A case of human to human transmission would raise fears that the bird flu virus could combine with a human flu
virus, to create a more deadly version of the disease.

The latest victim, named as Pranom Thongchan, is the second confirmed case since the latest outbreak began in July. She is reported to be recovering in hospital.

The woman's sister and 11-year-old niece both died earlier this month from severe pneumonia, and are listed as suspected bird flu cases. Test results are yet to be completed.

Health Minister Sudarat Keyuraphan said there was nothing to suggest the dead woman had contracted the disease from other humans.

"She had been in contact with dead chickens, together with her niece who died earlier," the minister said.

Charal Trinvuthipong, director general of the country's disease control department, said human to human transmission was only "an assumption".

"We do not have evidence to prove there is a transmission between humans," he said.

Six nations in the Asian region have reported outbreaks of bird flu in their poultry population since July, and more than 100 million birds have been culled this year in an attempt to stem the disease.

Three human deaths in Vietnam have also been attributed to bird flu since July.